1. Field of the Invention
The present invention relates to a device for controlling a valve of an internal combustion engine. More particularly, it relates to a device for selectively coupling two different rocker arms to the valve.
2. The Prior Art
Valve drives are known, for example, from German patent DE-PS 3,800,047. A first transmission lever is supported on a shaft in the cylinder head and is in engagement with the first cam for slightly opening the valve. The lever is supported on the valve via a compensation device which maintains contact therebetween. A second U-shaped transmission lever is in engagement with the cam halves of the second cam for maximum opening. A drive device selectively couples the second lever to the first transmission lever, i.e., to effect valve lift. The drive device is designed as a switchable, radial pin for coupling adjacent radial contours of the two transmission levers.
The drawback with such a design is that the drive device has a driver which produces a form lock when engaging a bore. The angular position and the axial position of the transmission levers have to be exactly right, i.e., when the large effective stroke is switched on, the drive device requires a centering function in both the axial and radial directions irrespective of oil pressure variations and has to be forcefully maintained in the form lock.